Yawning is genuinely contagious – which is why, once you spot someone yawning in your vicinity, it sets you off too.
Even reading the words “yawn” and “yawning” can cause you to break out in a case of the yawns… and the same is true of most people.
However there may be someone in your midst who remains immune to the outbreak.
And it’s probably a good idea to keep an eye on that person, as experts have now revealed that those who don’t find yawning contagious are almost definitely psychopaths.
A new study, published in Personality and Individual Differences, has revealed that ‘catching yawns’ is associated with empathy and bonding.
So much so that it’s a trait often observed in many social animals, including dogs and chimps.
However psychopaths – who are defined, in part, as lacking empathy – are immune to the phenomenon.
Lead researcher Brian Rundle explained: "You may yawn, even if you don't have to. We all know it and always wonder why. I thought, 'If it's true that yawning is related to empathy, I'll bet that psychopaths yawn a lot less.' So I put it to the test.”
He and his team asked 135 college students to take part in the Psychopathic Personality Inventory – a psychological test comprised of 156 questions.
They then showed participants clips of different facial movements, such as laughing, yawning, or neutral.
The results clearly showed that less empathetic people are far less likely to yawn after spotting someone else do it nearby.
The theory is not exactly a new one; immunity to contagious yawning is listed as a psychopathic trait on the Hare Psychopath Checklist.
And, as many Luther fans will no doubt be aware, Idris Elba’s character was pretty confident that Alice (Ruth Wilson) had killed her parents after he noticed that she didn’t yawn when he did.
While he never managed to prove her guilt, it was later revealed that she was a genius-IQ psychopath – and, while she went on to forge an alliance with Luther, let’s not forget that she was also a murderous stalker.
However, before you start a witch hunt at the office, Rundle issued an important reminder.
“The take-home lesson is not that if you yawn and someone else doesn't, the other person is a psychopath,” he explained.
“A lot of people didn't yawn, and we know that we're not very likely to yawn in response to a stranger we don't have empathetic connections with. But what we found tells us there is a neurological connection — some overlap — between psychopathy and contagious yawning. This is a good starting point to ask more questions."
Essentially, if you’re immune to yawns, you are more likely to identify with some psychopathic tendencies than others... but that doesn't mean you're guaranteed to turn into the next Hannibal Lecter.
At best, you may just be a little more selfish and disconnected from society than everybody else.
Anyone else suddenly feeling the urge to yawn...?